Evolution in the Light of Time: Conceptualizing the Extended Evolutionary Synthesis
thesisposted on 12.05.2020, 23:02 by Brian P HoburgBrian P Hoburg
Compelled by converging research in the natural sciences suggesting the stratigraphic nature of time, I argue for a temporal approach to the venerable problem of synthesis in evolutionary theory. Geneticist and pioneer of the Modern Synthesis (MS), Theodosius Dobzhansky (1900-1975), constructed one of the most powerful synthesis arguments in the history of evolutionary biology in the classic “Nothing in Biology Makes Sense Except in the Light of Evolution” (1973). I argue that nothing in evolution makes sense except in the light of time, such that the problem of evolutionary time plays a powerful role in making sense of the conceptual architecture of the Extended Evolutionary Synthesis (EES). The EES offers a strong alternative to the temporal and causal idealizations operating at the hardened core of the MS. I create the philosophical concept of stratigraphic time to strengthen connections between the four problem agendas or “causal catchalls” structuring the new synthesis: (1) developmental plasticity, (2) developmental bias, (3) inclusive inheritance, and (4) niche construction (Laland 2015 et al.). The dissertation is driven by two critical arguments (Chapters 1-3) concerning the subordination of time to process, and two constructive arguments (Chapters 4 and 5) concerning the nature of evolutionary time, which together attest to the conceptual strength of a temporal approach to the multiplicity of evolutionary problems pursued by the EES, and especially the connections between them.
Chapter 1, “Embracing the Problematic Structure of the Extended Evolutionary Synthesis,” explicates and evaluates the core assumptions of the EES in contrast with those of the MS, which has served as the dominant conceptual framework for evolutionary science and theory since the early twentieth century. Chapter 2, “Deep Time: The Forgotten Frontier,” critically argues that evolutionary time has been subordinated to evolutionary process, that the problem of evolutionary time must be revived after its eclipse at the origin of evolutionary theory, especially due to Darwin’s unnecessarily strict commitments to gradualism, adaptationism, and to the preeminence of natural selection. Chapter 3, “The Chronometric Subordination of Time to Movement in Philosophy, Science, and Society,” critically argues that the subordination of evolutionary time to process is primed by the chronometrically facilitated subordination of time to movement, what mathematician, physicist, and philosopher of science Henri Poincaré (1854-1912) called an unconscious opportunism in philosophical and scientific thought. The constructive arguments unfolded in Chapter 4, “The Continuous Variation of Evolutionary Contingency,” and Chapter 5, “Stratigraphic Time: The Synthesis of Deep and Developmental Rhythms,” attempt to respect causal thinking while conceptualizing evolutionary processes not according to causal laws but rather according to passive and active temporal syntheses (or modes of repetition), effectively delimiting causal thinking to a provisional conceptualization. Stratigraphic time enables conceptualization of the multiplicity of evolutionary process, driven by a new concept of evolutionary contingency. I argue that the roles of chance and causation in the EES are strengthened by concepts of difference and repetition, akin to the conceptual roles played by arrows and cycles of time in the formation of geological and evolutionary thought. These critical and constructive arguments are guided by Gilles Deleuze’s philosophy of time, which he conceptualizes under the rubric of repetition. The three passive and active temporal syntheses, or modes of repetition, Deleuze creates to think the nature of repetition provide conceptual tools for evolutionary synthesis through stratigraphic time.